This invention relates to a lock shielding assembly and more particularly to an assembly for shielding the key receiving aperture of a door lock, or the like, so as to prevent the insertion of a key into the key hole of the lock by an unauthorized person.
With the increase in theft, there has resulted a trend towards providing security devices and auxiliary apparatus which can be attached to existing locks to increase the security of the lock mechanism. While conventional locking devices require a specific key to open them, most lock operating mechanisms such as pin tumbler locks can be picked by a skillful thief and have been shown to be ineffective in providing sufficient security. As a result, mechanisms have been provided to shield the lock from an unauthorized person so that he cannot reach the lock cylinder to pick the lock.
Many of these auxiliary apparatus attach to the door or other area supporting the conventional lock, and provides a cover over the conventional lock which is in turn secured to the door or to a separate housing. One such door attachment is shown and described in U.S. Pat. No. 2,883,849. This patent describes a lock shielding attachment which includes a support plate having guides through which a cover plate can slidably move. Forward projecting integral ears on both the support plate and the cover plate have registered apertures through which a padlock can be inserted to retain the cover plate in a closed position shielding access to the conventional lock.
Another such shielding mechanism is described in U.S. Pat. No. 3,714,804 which utilizes an armored cover plate and shutter mechanism, wherein the shutter plate can move between a blocking and unblocking position. The shutter plate is supported by a rotating gate and is retained in a closed position by means of an outwardly extending leg which includes an aperture aligned with a ring on the outer housing. Again a padlock is used to secure the plate to the housing.
These, and other similar apparatus although shielding the lock, can be ripped off and removed to provide access to the lock cylinder. For example, the padlock can be broken by force or its hasp can be cut. Additionally, the flat surfaces of the shielding apparatus permit them to be forced open by hammering or ripping off the entire apparatus.
It has been found that one of the best deterrents to theft is not so much the actual provision of an auxiliary apparatus to shield the lock, but the amount of time needed to break into or open the apparatus. For example, the most complex apparatus provides little deterrent if it can be removed by force in a short period of time. On the other hand, a more simplified apparatus provides a better measure of security if it requires a greater amount of time for a thief to force or break open.